Calculus/calculi retrieving device and method

ABSTRACT

A method of retrieving calculus in a living body and relocating the calculus to a different location in the living body involves positioning an elongated member in the living body in which the calculus is located, drawing the calculus in the living body toward the elongated member while the elongated member is positioned in the living body so that the calculus is retained by the elongated member; moving the elongated member so that the elongated member is located at a position in the living body that is different from the position of the elongated member in the living body during the drawing of the calculus toward the elongated member; and releasing the calculus from the elongated member so that the calculus is at a position in the living body different from a location of the calculus in the living body while the calculus is being drawn toward the elongated member.

CROSS-REFERENCE TO OTHER APPLICATIONS

This application is a divisional of U.S. application Ser. No. 14/671,083filed Mar. 27, 2015 and discloses subject matter related to subjectmatter described in U.S. application Ser. No. 14/222,021, U.S.application Ser. No. 14/221,954 and U.S. application Ser. No.14/221,858, the entire content of all four of which is incorporatedherein by reference.

TECHNICAL FIELD

The present invention generally pertains to methods, systems and devicesfor retrieving a mass from a human body. More specifically, theinvention involves methods, devices and systems for retrieving stone(s)(e.g., calculus or calculi) from a portion of a human body, and movingthe retrieved stone(s) to a different location in the living body.

BACKGROUND DISCUSSION

The term urinary calculus (e.g., kidney stones and ureteral stones)refers to masses or stones, typically solid particles, that form in thehuman body and are located in the kidneys and/or the ureter. Calculuscan exhibit a variety of chemical compositions including calciumoxalate, calcium phosphate, uric acid, cystine, and struvite.

Stone disease (e.g., kidney stones and ureteral stones) is a relativelycommon urological disorder. The presence of calculus in the body canmanifest itself in a variety of ways and can produce a number of medicalailments. For example, the presence of calculus in the renal pelvisand/or the renal calix (i.e., the lumen of the kidney) can cause bloodin the urine, urinary obstruction, infection, and various degrees ofpain ranging from vague frank pain to much more severe pain not capableof being relieved through general pain medication. The presence ofstones or calculi in the ureter can result in relatively severe side andback pain, pain below the ribs, and pain that sometimes spreads to thelower abdomen and groin, as well as pain during urination and hematuria.

Fortunately, many calculi or stones pass out of the body withoutrequiring any specific medical intervention. In those situations wherethe calculus does not naturally pass out of the body, a medicalprocedure may be required.

In the past, three main treatments have been used to treat or addresscalculus or kidney stones. These include shock wave lithotripsy (ESWL),transurethral lithotripsy or ureteroscopy (URS), and percutaneousnephrouretero lithotripsy (PCNL) which is sometimes also referred to aspercutaneous nephrolithotomy (PCN).

Shock wave lithotripsy is performed as an extracorporeal treatment. Thistreatment utilizes a machine called a lithotripter that operates bydirecting ultrasonic or shock waves from outside the body, through theskin and tissue, and at the calculi or stones. Repeated shock wavesapply stress to the stones, eventually breaking the individual stonesinto smaller pieces which can more easily pass through the urinary tractin urine. One benefit associated with shock wave lithotripsy is that itis a rather simple procedure. But it has been found that there is arelatively high rate of kidney stone recurrence following shock wavelithotripsy.

Transurethral lithotripsy or ureteroscopy represents one suchalternative form of treatment. This treatment involves the use of smallfiber optic instrument called a ureteroscope which allows access to thecalculus in the ureter or kidney. The ureteroscope can be a rigidureteroscope or more commonly, a flexible ureteroscope. The ureteroscopeallows the medical professional to visualize the stone as theureteroscope moves along the ureter or enters the kidney by way of thebladder and the urethra. Once the calculus is visualized, a basket-likedevice is used to grasp smaller stones and remove them. If the calculusis excessively large to remove as a single piece, it can be broken intoa smaller pieces by using laser energy.

The third form of treatment is percutaneous nephrolithotomy. Thisprocedure is often used with relatively larger calculus that cannot beeffectively treated with either ESWL or URS. Percutaneousnephrolithotomy involves nephrostomy; making an incision at theappropriate location, needling by paracentesis needle, positioning aguide wire through the paracentesis needle's lumen into the kidney underradiographic guidance, and then expanding perforated site. A nephroscopeis then moved into the kidney via nephrostomy to visualize the calculus.Fragmentation of the calculus can be performed using an ultrasonic probeor laser.

Though these procedures have been commonly used, they are susceptible ofcertain short comings. For example, the calculus may be located at aplace in the living body that is not conducive to treatment bylithotripsy. The calculus may be located in a region of damaged tissueand/or may be located in a small space that is difficult to access withappropriate instrumentation.

SUMMARY

One aspect of the disclosure here involves a device for retrievingcalculus in a lumen of a living body, wherein the device comprises ashaft an elongated member sized to be positioned in the lumen of theliving body, a rotatable impeller positioned inside the elongatedmember, and a shaft cover. The elongated member includes a suction headhousing possessing a distal end, a proximal end and an interior, withthe distal end of the suction head housing being open to permit entry ofcalculus and the proximal end of the suction head housing being closedby a wall through which passes the shaft. The shaft is connected to therotatable impeller so that the shaft and the rotatable impeller rotatetogether as a unit. The shaft is connectable to a drive source that isoperable to rotate the shaft and the rotatable impeller, with rotationof the rotatable impeller creating suction that draws calculus throughthe open distal end of the suction head housing and into the interior ofthe suction head housing. The shaft cover possesses a distal end portionthat terminates in a distal end connected to the proximal end of thesuction head housing so that the elongated member and the shaft coveraxially move and rotate together. The shaft cover also possesses aproximal end portion and covers the shaft. The central axis of thedistal end portion of the shaft cover and the central axis of theproximal end portion of the shaft cover are non-coaxial.

According to another aspect, a device for retrieving calculus in a lumenof a living body comprises: an elongated member sized to be positionedin the lumen of the living body, the elongated member including asuction head housing disposed on a distal side of the elongated member;a rotatable member positioned inside the elongated member; a shaftconnected to the rotatable member so that the shaft and the rotatablemember move together as a unit, the shaft being connectable to a drivesource to rotate the shaft and the rotatable member, with rotation ofthe rotatable member creating suction that draws calculus toward theelongated member; a shaft cover possessing a distal end portion having acentral axis and a proximal end portion having a central axis, the shaftcover covering the shaft and being connected to the elongated member sothat the elongated member and the shaft cover axially move and rotatetogether; and the central axis of the distal end portion of the shaftcover is offset from the central axis of the proximal end portion of theshaft cover.

Other features and aspects of the calculus retrieving device and methoddisclosed here will become more apparent from the following detaileddescription considered with reference to the accompanying drawingfigures in which like elements are designated by like referencenumerals.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic illustration of a system useful to retrievecalculus/calculi, including a retrieving device connected to anoperation member (not shown in FIG. 1) through the intermediary of alumen in an elongated body.

FIG. 2 is a side view, partially in cross section, of a retrievingdevice according to an embodiment representing an example of theretrieving device disclosed here.

FIG. 3 is a front view of the impeller forming a part of the retrievingdevice shown in FIG. 2.

FIG. 4 is a schematic illustration of a portion of the human anatomy,including the urinary tract.

FIG. 5 is an schematic illustration of a human kidney.

FIG. 6 is a schematic illustration of the retrieving system, includingthe retrieving device connected to the operation member through theintermediary of an elongated body such as a ureteroscope.

FIG. 7A illustrates an example of calculus in a living body beingretrieved by the retrieving device, FIG. 7B is a schematic illustrationof the retrieving device being moved to move the retrieved calculus to adifferent location in the living body, and FIG. 7C is a schematicillustration of the calculus retrieving device, as the calculuspreviously retrieved is released.

FIG. 8 is a prospective view of the shaft cover forming a part of theretrieving device shown in FIG. 1.

FIG. 9 is a schematic illustration of an embodiment of the retrievingdevice representing another example of the retrieving device disclosedhere.

FIG. 10A is a side view of the retrieving device outfitted with theshaft cover shown in FIG. 8 according to one operational aspect, FIG.10B illustrates the retrieving device according to another operationalaspect after moving the suction head in the rearward direction to orientthe suction head at an angle relative to the elongated body, FIG. 10Cillustrates the retrieving device shown in FIG. 10A according to anotheroperational aspect in which the suction head is rotated 180° from theposition shown in FIG. 10B, FIG. 10D illustrates the retrieving deviceshown according to an further operational aspect in which the suctionhead is moved forwardly to position the suction head at a locationpermitting viewing, by way of the ureteroscope, and FIG. 10E illustratesthe retrieving device according to an further operational aspect inwhich the shaft cover is pulled from the position shown in FIG. 10B.

FIG. 11A is a side view of an embodiment of the retrieving devicerepresenting another example of the retrieving device disclosed here inwhich the retrieving device is configured to angle the suction headrelative to the ureteroscope. FIG. 11B illustrates the retrieving deviceaccording to another operational aspect after moving the suction head inthe rearward direction so that the suction head is angled relative tothe ureteroscope, and FIG. 11C illustrates the retrieving device shownin FIG. 11A according to another operational aspect in which the suctionhead is rotated 180° from the position shown in FIG. 11A.

FIG. 12A is a side view of an embodiment of the retrieving devicerepresenting an additional example of the retrieving device disclosedhere in which the retrieving device is configured to angle the suctionhead relative to the ureteroscope, and FIG. 12B illustrates theretrieving device according to another operational aspect after movingthe suction head in the rearward direction so that the suction head isangled relative to the ureteroscope.

FIG. 13A is a side view of an embodiment of the retrieving devicerepresenting another example of the retrieving device disclosed here inwhich the retrieving device is configured to angle the suction headrelative to the ureteroscope, and FIG. 13B illustrates the retrievingdevice according to another operational aspect after moving the suctionhead in the rearward direction so that the suction head is angledrelative to the ureteroscope.

FIG. 14A is a side view of an embodiment of the retrieving devicerepresenting a further example of the retrieving device disclosed herein which the retrieving device is configured to angle the suction headrelative to the ureteroscope, and FIG. 14B illustrates the retrievingdevice according to another operational aspect after moving the suctionhead in the rearward direction so that the suction head is angledrelative to the ureteroscope.

FIG. 15A is a side view of an embodiment of the retrieving devicerepresenting another example of the retrieving device disclosed here inwhich the retrieving device is configured to angle the suction headrelative to the ureteroscope, and FIG. 15B illustrates the retrievingdevice according to another operational aspect after moving the suctionhead in the rearward direction so that the suction head is angledrelative to the ureteroscope.

FIG. 16A is a side view of an embodiment of the retrieving devicerepresenting another example of the retrieving device disclosed here inwhich the retrieving device is configured to angle the suction headrelative to the ureteroscope, FIG. 16B illustrates the retrieving deviceaccording to another operational aspect after moving the suction head inthe rearward direction, and

FIG. 16C illustrates the retrieving device shown in FIG. 16B accordingto another operational aspect in which the suction head is rotated 180°from the position shown in FIG. 16C.

DETAILED DESCRIPTION

Set forth below is a detailed description of features and aspects of theretrieving system, device and method described here as examples of thedisclosed invention. The methods, systems, and devices disclosed herefor retrieving have particularly useful application to retrievecalculus/calculi located in the living body, including calculus/calculilocated in the ureter (ureter stones) and calculus located in thekidneys (kidney stones), though the methods, systems and devices are notlimited in this regard. The references below to calculus should beunderstood to refer to calculus in the singular as well as calculi inthe plural.

Generally speaking, the calculus removing/retrieving device disclosedhere, as represented by the several embodiments representing examples ofthe inventive retrieving device (and method), is configured to bepositioned inside a living body at a position which will allow theretrieving device to suck-in or draw-in calculus to be retrieved. Setforth below is a detailed description of features and aspects of thecalculus retrieving system, including a calculus retrieving device, andmethod described here by way of various embodiments representingexamples of the disclosed inventions. The systems, devices and methodsdisclosed here for retrieving calculus have particular usefulapplication to retrieve calculus located at places in the human body,where removal of the calculus may be difficult.

Generally speaking, the calculus retrieving device disclosed here, ascharacterized by the several embodiments representing examples of theinventive calculus retrieving device (and method), is configured to bepositioned inside a living body, at a position adjacent the location ofcalculus to be retrieved from the living body and moved to a new(different) location in the living body. The calculus (stone/stones) isdrawn towards the retrieving device by creating a suction force in theretrieving device. After the calculus is retrieved, the calculus isretained or held by the retrieving device, and the retrieving device ismoved to the new location in the living body at which the retrievedcalculus is to be repositioned. The retained calculus is subsequentlyreleased at the new location in the living body. Appropriate procedures(e.g., lithotripsy) can then be performed with respect to the calculuswhich has been moved

Turning now to the drawing figures, FIG. 1 illustrates, in a schematicfashion, a system 20 for retrieving and moving calculus (stone orstones) located in a living body. The system 20 includes a retrievingdevice 30 and an elongated body 40 possessing a lumen to deliver theretrieving device 30 to the desired place in the living body. In thisillustrated embodiment representing one example of the system disclosedhere, the elongated body 40 is a ureteroscope. The ureteroscope includesa lumen or instrument channel 42, which receives a portion of theretrieving device 30, as will be described in more detail below. Duringuse of the retrieving device 30, the ureteroscope 40 is introduced intothe living body by way of a ureteral access sheath 24. The ureteroscope40 passes through a lumen 28 in the ureteral access sheath 24.

Additional details and features associated with the calculus retrievingdevice 30 can be seen with reference to FIGS. 1, 2 and 3. The calculusretrieving device 30 includes a suction head 50 that includes anelongated body or housing 51 having an open distal end 52. The housing51 is a tubular housing possessing a lumen 54 defining an interior ofthe housing 51. The housing 51 can be configured as a cylindricalelongated body or housing.

The retrieving device 30 also includes a rotatable suction-producingpart located inside the housing 51. In the illustrated embodiment, therotatable suction-producing part is in the form of an impeller 60. Asshown in FIGS. 1 and 3, the impeller is positioned in the housing 51 ata location spaced away from (i.e., proximally or rearwardly) the opendistal end 52. An example of the impeller 60 is illustrated in FIG. 3.The impeller 60 includes a plurality of circumferentially spaced apartfins or blades 62 that are fixed to a central hub 64. The fins or blades62 of the impeller 60 may be twisted fins or blades. The hub 64 is fixedor connected to a rotatably driven shaft 72 so that the shaft 72 and theimpeller 60 rotate together as a unit. The impeller 60 is configured sothat rotation of the impeller 60 in one rotational direction producessuction in the lumen 54 (in the interior) of the housing 51, whilerotation of the impeller 60 in the opposite rotational directionproduces the opposite result, namely an outwardly directed force out ofthe lumen 54. The blades 62 of the impeller 60 shown in FIGS. 2 and 3are preferably twisted from the distal tip of the blades 62 (radiallyoutermost tip of the blades) toward the bottom portion of the impellerwhere the blades are mounted. When the direction of the impellerrotation is the same as the twist direction of the blades 62, a suctionforce is generated. This direction of rotation of the impeller isreferred to as overspin direction.

The drive shaft 72 that is connected to the hub 64 of the impeller 60 ispositioned inside of and covered by a shaft cover 70. In the illustratedembodiment, the drive shaft 72 is completely covered by the shaft cover70. The shaft cover 70 is fixed to the housing 51 forming the suctionhead 50 so that movement of the shaft cover 70 results in movement ofthe suction head 50 (including the housing 51 and the impeller 60).

The housing 51 forming the suction head 50 includes a plurality ofcircumferentially spaced apart openings or through holes 54. Theseopenings or through holes 54 are positioned closer to the proximal endof the housing 51 than the distal end of the housing 51. These openingsor through holes 54 form an exhaust path during operation of theretrieving device, as will become more apparent from the descriptionbelow. That is, liquid (e.g., water) which has been drawn into thehousing 51 of the suction head 50 during operation of the retrievingdevice 30 is exhausted or discharged out of the suction head 50 by wayof the openings or through holes 54.

The suction head 50 further includes a filter 56 located inside thehousing 51 at a position between the distal end of the impeller 60 andthe open distal end 52 of the suction head 50. This filter 56 is adisc-shaped mesh member that allows the passage of fluid (e.g., liquidsuch as water), while also preventing the passage of calculus which hasbeen retrieved through operation of the retrieving device 30. The filter56 possesses an outer periphery (outer circumferential surface) incontact with the inner periphery of the suction head 50. The filter 56is positionally fixed within the interior of the housing 51 forming thesuction head 50.

The suction head 50 also includes a retrieval space 58 located betweenthe filter 56 and the open distal end 52 of the housing 51. As will bedescribed in more detail below, this retrieval space 58 is configured toreceive calculus which has been retrieved as a result of the operationof the retrieving device 30.

During operation of the retrieving device 30, the suction head 50 islocated at a position in a living body to retrieve calculus. That is,the suction head 50 is positioned relative to the calculus to beretrieved such that during operation of the retrieving device 30, thecalculus will be drawn towards (sucked towards) the suction head 50.When the suction head 50 is properly positioned relative to the calculusto be retrieved, the impeller 60 is rotatably driven through operationof a drive device connected to the drive shaft 72. The drive devicerotates the drive shaft 72, which in turn rotates the impeller 60. Theimpeller 60 is rotatably driven in a direction to create a suction inthe interior of the housing 51 that draws calculus toward the opendistal end 52 of the suction head 50. The suction force created by therotation of the impeller 60 draws relatively smaller calculus(schematically shown in FIG. 1 and identified as 68) through the opendistal end 52 of the suction head and into the retrieval space 58 in thehousing 51. The suction force created by the rotation of the impeller 60can also draws relatively larger calculus into contact with the distalend of the suction head 50. That is, calculus possessing an outerdimension larger than the size of the open distal end 52 of the suctionhead 50 can nevertheless be drawn towards the suction head 50 andretained by the suction head 50 by creating sufficient suction force inthe interior of the housing 51 that holds the relatively larger calculusin contact with the distal end of the suction head 50.

Thus, by positioning the suction head 50 in the living body so that theopen distal end 52 of the suction head 50 is located at a position thatwill allow the calculus (i.e., calculus to be retrieved) to bedrawn-into or sucked into the retrieval space 58 upon rotationaloperation of the impeller 60, it is possible to retrieve calculus andhold the retrieved calculus either in the retrieval space 58 or at thedistal end of the suction head 50. As the impeller 60 is rotated to drawcalculus toward the suction head 50, liquid (e.g., water) is drawn intothe retrieval space 58 by way of the distal open end 52 of the suctionhead 50. This liquid is passes through the filter 56, and is exhaustedor discharged outside the housing 51 of the suction head 50 through theopenings or through holes 54. On the other hand, the filter 56 is sizedto ensure that calculus which is drawn into the retrieval space 58 ofthe suction head 50, does not pass through the filter 56. The rotationaloperation of the impeller 60 thus causes liquid flow in which liquidenters the distal open end 52 of the suction head 50, passes through thefilter 56, and exits through the through holes or openings 54 in thesuction head 50. Depending upon operation of the impeller 60, the liquidexhausted through the openings or through holes 54 can also be at leastpartially drawn back into the interior of the suction head 50, thuscreating a rather turbulent and continuous liquid cycle in which thesame liquid is repeatedly drawn into the suction head, exhausted throughthe suction head 50, drawn into the suction head, etc. This turbulentand continuous liquid cycle can help facilitate retrieval of calculus inthe retrieval space 58 of the suction head 50. This is because thesuction force per rotation of the impeller is increased. In addition,the calculus tends to float, making it easier to draw-in or retrieve thecalculus. When drawing-in calculus in a narrow lumen in a living body(e.g. ureter), the continuous liquid cycle helps prevent fluidsurrounding calculus from drying up.

Set forth next is a description of contexts in which the system forretrieving calculus disclosed here can be used, as well as a descriptionof a manner of operation of the system for retrieving calculus. It issometimes necessary or desirable to break-up calculus located in aliving body. For instance, calculus that is relatively small can bepulled out of the body, but if the calculus is relatively large (e.g.,larger than the ureter diameter), it is not possible to remove thecalculus from the living body. In such situations, it would be desirableto break-up the calculus into smaller size pieces. This can oftentimesbe accomplished using lithotripsy. But circumstances may make itdifficult to perform lithotripsy to break-up calculus in the livingbody. For example, the calculus may be located at a place where damagedtissue exists, for example in a portion of the ureter in which there isdamaged tissue. Alternatively, the calculus may be located in a portionof the living body (e.g., ureter) that is rather small in size (i.e., anarrow space) and difficult to access with appropriate instrumentationand equipment for performing lithotripsy (e.g., a lower calix). Theapproach described here involves retrieving the calculus, moving theretrieved calculus to a new (different) location which presents a largerspace (e.g., the kidney or an upper calix) to perform lithotripsy orwhich presents a region where there is normal (non-damaged tissue)tissue.

The retrieving device and system disclosed here are configured toretrieve calculus from one place in the living body, move the retrievedcalculus to a new (different) place where, for example, lithotripsy canbe more easily performed to break-up the calculus, and then release theretrieved and moved calculus at the new location. By way of example, andwith reference to FIG. 4, it is possible to retrieve calculus at thelocation X in the ureter (representing an example of a region of narrowsize or damaged tissue) and move the retrieved calculus to the positionX′ in the ureter (representing an example of a region of larger size ornormal non-damaged tissue). It is also possible to retrieve calculus atthe location Y (representing an example of a region of narrow size ordamaged tissue) and move the retrieved calculus to the position in thekidney (representing another example of a region of larger size ornormal non-damaged tissue).

To retrieve and move the calculus, the retrieving system 20 shown inFIG. 6 is used. Specifically, the calculus retrieving device 30 is used,together with the operating member 26 and the ureteroscope 40. Theoperating member 26 is connected to the shaft cover 70, so thatoperation of the operating member 26 causes the shaft cover 70 to move.That is, the operation of the operating member 26 causes the shaft cover70 to axially move, which in turn causes the suction head 50 (includingthe impeller 60 and the filter 56) to also axially move. FIG. 6schematically illustrates that the shaft 72 positioned within andextending along the axel length of the shaft cover 70 is connected to adriving source 28. Operation of the driving source 28 rotates the shaft72, which in turn rotates the impeller 60 positioned in the housing 51of the suction head 50 of the calculus retrieving device 30. As shown inFIG. 6, the shaft cover 70 and the shaft 72 extend from the operatingmember 26, enter an inlet 44 of the instrument channel 42 in theureteroscope 40, pass through the ureteroscope 40, and exit at an outletat the distal end portion 46 of the ureteroscope 40.

In use, the shaft cover 70 is connected to the housing 51 of the suctionhead 50, and the proximal end of the shaft cover 70 and the shaft 72 areinserted into the outlet of the instrument channel 42 at the distal endportion 46 of the ureteroscope 40. The shaft cover 70 and the shaft 72are pushed through the lumen (instrument channel 42) in the ureteroscope40 until the proximal end of the shaft cover 70 and the proximal end ofthe shaft 72 exit out of the inlet 44 of the ureteroscope. The proximalend of the shaft 72 is then connected to the driving device 28, whilethe proximal end of the shaft cover 70 is fixed to the operating member26.

The ureteroscope 40 is preferably a flexible ureteroscope. Theureteroscope 40 includes a viewing system that includes an objectivelens 48 schematically illustrated in FIGS. 1 and 6. In a known manner,this provides a field of view for the user or operator to facilitatecarrying out the procedure involving locating calculus, retrieving thecalculus, moving the calculus to the new location and releasing thecalculus at the new location.

Next, the retrieving device 30, arranged distally of the ureteroscope 40as shown in FIG. 6, is introduced into the living body. This can beaccomplished by way of the ureteral access sheath 24 schematically shownin FIG. 1. Once the retrieving device 30 is introduced into the livingbody, the retrieving device 30 is advanced to the desired positionwithin the living body through operation of the operating member 26. Theretrieving device 30 is preferably positioned so that the open distalend 52 of the suction head 50 is positioned near to or adjacent thecalculus/calculi to be retrieved. That is, the retrieving device 30 ismoved to locate the open distal end 52 at a position relative to thecalculus to be retrieved such that during operation of the suction head50 (rotation of the impeller 60), the resulting suction draws calculustoward the suction head 50.

After the suction head 50 is properly positioned relative to thecalculus to be retrieved, the driving source 28 (e.g., a geared motor)is operated to rotate the impeller 60 in a direction which causessuction to be created in the interior of the suction head 50. Thiscauses the calculus to be sucked or drawn toward the distal open end 52of the suction head and into the retrieval space 58 at the distal endportion of the suction head 50 (assuming the calculus is sufficientlysmall). As described above, as the calculus is drawn towards the suctionhead 50 (into the retrieval space 58), liquid is also drawn into thesuction head 50. This liquid is able to pass through the filter 56, andis exhausted through the openings 54. On the other hand, the filterprevents the calculus which has been drawn into the retrieval space 58from passing through the filter 56. The retrieved calculus which hasentered the retrieval space thus remains in the retrieval space 58.

FIGS. 7A-7C depict three aspects of the method disclosed here involvingretrieving calculus 68 through operation of the suction head 50 (FIG.7A), moving the suction head 50 and the retrieved calculus 68 to a newlocation (FIG. 7B), and releasing the calculus 68 (FIG. 7C). FIG. 7Agenerally illustrates calculus 68 that has been drawn towards thesuction head 50 and is held against the open distal end 52 of thesuction head 50. In this illustrated version, the retrieved calculus 68possesses an outer dimension greater than the inner dimension of thelumen (retrieval space 58) in the suction head 50. This possibility isonly for illustrative purposes, and it is to be understood that asimilar operation is performed to retrieve smaller calculus that areable to pass through the open distal end 52 of the suction head and bepositioned inside the retrieval space 58, such as schematicallyillustrated in FIG. 1.

The retrieval of the calculus 68, the retention of the calculus 68during movement of the suction head 50, and the release of the retrievedcalculus can be accomplished by controlling various operationalparameters of the suction head 50. These operational parameters includethe rotation operation of the impeller 60 (ON/OFF), the rotation speedof the impeller 60, and the rotation direction of the impeller. That is,by varying the rotation operation, the rotation speed and the rotationdirection of the impeller 60, it is possible to control the retrieval,the retention and the release of the calculus.

During retrieval of the calculus, the impeller 60 is preferably rotated(i.e., the rotational operation is ON), is rotated at a relatively highspeed (e.g., 15,000 rpm-20,000 rpm), and is rotated in the overspindirection intended to create suction in the suction head 50. Thecalculus 68 is thus drawn toward the open distal end 52 of the suctionhead 50. If the calculus 68 is smaller than the open distal end 52 ofthe suction head 50, the calculus 68 will enter the retrieval space 58as shown in FIG. 1. If the calculus 68 is larger than the open distalend 52 of the suction head 50, the calculus 68 will be held against thedistal end of the suction head as shown in FIGS. 7A-7C.

After the calculus 68 has been retrieved, it is necessary to retain theretrieved calculus 68 in the retrieval space 58 of the suction head 50or against the distal end of the suction head 50 while moving thesuction head 50 to transport the retrieved calculus 68 to the new(different) location. To retain the retrieved calculus 68, the drivingdevice 28 continues to operate (i.e., the rotational operation is ON) sothat the impeller 60 continues rotating. The rotation direction of theimpeller 60 is the same as the rotation direction of the impeller duringretrieval of the calculus. In addition, the rotation speed of theimpeller 60 can be the same relatively high speed as the rotation speedof the impeller 60 during retrieval of the calculus/calculi, or can be aslightly slower rotation speed (e.g., 12,000 rpm-15,000 rpm).

While operating the suction head in the above described manner to retainthe retrieved calculus 60, the suction head 50 is moved throughoperation of the operating member 26 to position the open distal end 52of the suction head 50 at the new location where the retrieved calculusis to be released. When the suction head reaches this position, it isnow necessary to operate the suction head 50 to release the calculus 68.To do this, the operator turns off the operation of the driving source28 so that the retention power disappears and then the retrievedcalculus 60 drops from the open distal end 52 of the suction head 50naturally. In this rotation-OFF state, the retrieved calculus 60retained in the retrieval space 58 can be rather easily released bysmall movement of the suction head 50. In the situation that the releaseof the calculus 68 should be controlled more exactly or accurately, orthe retrieved calculi 60 are difficult to release from the retrievalspace 58 because the calculi 60 may be jammed in the retrieval space 58,the operator can change the operation of the driving source 28 so thatthe driving source rotates the shaft 72 and the impeller 60 in thedirection opposite the rotational direction of the impeller and theshaft during retrieval and retention of the calculus/calculi. That is,the impeller 60 is operated in the backspin direction. The rotationalspeed of the impeller 60 during release of the calculus is preferablyslower than the rotational speed of the impeller 60 during retention ofthe calculus 68 when the suction head 50 is being moved to the newlocation.

After releasing the retrieved calculus 68, the retrieving device 30 isremoved from the living body, or is moved to a position in the livingbody to retrieve other calculus.

As described above, the calculus is preferably retrieved from a portionof the living body which is not well suited to removing the calculus andwhich does not lend itself to the use of lithotripsy. The use of theretrieving device 30 thus allows the calculus to be retrieved and movedto another location at which lithotripsy can be used to break-up thecalculus into smaller pieces so that the smaller pieces can either beremoved from the body naturally or by use of appropriateinstrumentation. The description above describes use of the retrievingdevice 30 to retrieving calculus and moving the retrieved calculus to anew location in the living body. But the retrieving device disclosedhere is not limited to this manner of use. For example, it is possibleto use the retrieving device 30 as an instrument for removing calculusfrom a living body.

FIG. 9 illustrates a slight variation on the configuration of thesuction head described above and illustrated in FIGS. 1, 2 and 6. Theembodiment of the suction head 50′ illustrated in FIG. 9 includes agel-like material 53 that is located at the open distal end of thesuction head 50′. The gel-like material 53 constitutes a compressiblemember 53 that helps to facilitate the retention of the calculus 68 onthe suction head so that, for example, the calculus 68 does not becomeseparated from the suction head while the calculus is being conveyed tothe new location. The gel-like material 53 provides a greater area ofcontact with the retrieved calculus 68 than would otherwise be the case.Examples of the gel-like material 53 include silicone, soft rubber andpolyurethane. The gel-like material 53 can be used when it is expectedthat the size of the calculus 68 being retrieved is larger than theopening at the distal end of the suction head 50′. The gel-like materialcan also be provided at the end of the suction head if small calculusthat enter the retrieval space are being retrieved.

Another aspect of the retrieving device disclosed here is the ability ofthe retrieving device to retrieve calculus located in regions of theliving body that are highly curved and require significant and severemanipulation to reach. The retrieving device includes a particularlyconfigured shaft cover 70 covering the shaft 72. As described above, thedistal end of the shaft cover 70 is connected or fixed to the suctionhead. FIG. 1 generally illustrates the configuration of the shaft cover70, while FIG. 8 illustrates the configuration of the shaft cover inmore detail.

Referring to FIG. 8, the shaft cover 70 includes a distal section 75, aproximal section 77 and an intermediately located bent section 79positioned between the distal section 75 and the proximal section 77. Inthe illustrated embodiment, the distal section 75 and the proximalsection 77 are linearly extending (straight) sections. Theintermediately located bent section 79 is bounded on opposite ends byrespective bends 79′. The distal section 75 extends from the distal end71 of the shaft cover 70 to the intermediately located bent section 79,and the proximal section 77 extends from the proximal end 73 of theshaft cover 70 to the intermediately located bent section 79. The bentsection 79 is a stiff bent section, meaning that if the bent section 79is not surrounded by or influenced by a rigid lumen, the bent section 79is always bent, by virtue of the bends 79′, relative to the proximalsection 77 and the distal section 75. That is, in the absence of a forceor load (external or internal) applied to the bent section, the bentsection 79 remains bent. On the other hand, when the bent section 79 isinserted into or positioned in the instrument channel 42 of theureteroscope, a force or load is applied to the bent section 79 by thestraight instrument channel 42 and so the shape of the section 79 ischanged from bent to straight (i.e., the bent section 79 is straightenedout). When the bent section 79 located in the instrument channel 42 ofthe ureteroscope is pulled out of the instrument channel 42, the bentsection 79 automatically returns to its bent configuration.

The distal end 71 of the shaft cover 70 is connected or fixed to thesuction head 50 while the proximal end 73 of the shaft cover 70 isconnected to the operating member 26. In the illustrated embodiment, thecentral axis of the distal section 75 and the central axis of theproximal section 77 are parallel to one another, but offset from oneanother so that the proximal section 77 and the distal section 75 arenot coaxial.

FIG. 8 shows that the proximal section 77 of the shaft cover 70 includesthree portions, namely the distal portion 70 b of the proximal section77, the intermediate portion 70 c of the proximal section 77, and theproximal portion 70 d of the proximal section 77. The distal portion 70b of the proximal section 77 is preferably made of a material that isrelatively stiff or rigid. The purpose for this relatively stiff orrigid material is to keep the tip positioned position so that thesuction head 50 does not bow under its own weight. Appropriate materialcan be rubber or plastic material. The intermediate section 79 and thedistal section 75 of the shaft cover 70 are preferably also made ofrelatively stiff or rigid material. The intermediate section 79 and thedistal section 75 of the shaft cover 70 can be fabricated from the samematerial forming the distal portion 70 b of the proximal section 77.

The intermediate portion 70 c of the proximal section 77 is preferablymade of a relatively soft material. The material forming theintermediate portion 70 c of the proximal section 70 is softer than thematerial forming the distal portion 70 b of the proximal section 77. Thematerial forming the intermediate portion 70 c of the proximal section77 is thus a material that is more flexible than the relatively stiff orrigid material forming the distal section 70 b of the proximal section77. In other words, the intermediate portion 70 c of the proximalsection 77 is more flexible than the distal portion 70 b of the proximalsection 77. The purpose of this material is to help prevent theintermediate portion of the proximal section from negatively impactingthe ability of the ureteroscope to deflect.

The proximal portion 70 d of the proximal section 77 is made of arelatively stiff or rigid material that is specifically selected toensure appropriate torque transmission. That is, the material formingthe proximal portion 70 d is preferably selected so that torque appliedto the proximal portion of the proximal section (e.g., by way of theoperating member 26) is appropriately transmitted toward the distalsection of the shaft cover 70. The stiffness of the proximal portion 70d is preferably greater than the stiffness of the distal portion 70 b.

To provide an example of the relative lengths of the portions 70 b, 70c, 70 d forming the proximal section 77 of the cover shaft, the distalportion 70 b of the proximal section 77 is preferably 6 mm-15 mm inlength, more preferably 8 mm in length, the intermediate portion 70 c ispreferably 60 mm-150 mm in length, more preferably 80 mm in length andthe proximal portion 70 d of the proximal section 77 is preferably 800mm-1200 mm in length, more preferably 1000 mm in length. Thus, thedistal portion 70 b of the proximal section 77 is shorter than theintermediate portion 70 c and the proximal portion 70 d of the proximalsection 77, and the intermediate portion 70 c is shorter than theproximal portion 70 d of the proximal section 77. In addition, theintermediate section can possess a length of preferably 1 mm-3 mm, morepreferably approximately 2 mm while the distal section 75 possesses alength of preferably 3 mm-8 mm, more preferably about 5 mm.

As described above, the intermediately located bent section 79 isbounded on opposite ends by bends 79′, 79′. As will be described in moredetail below, the bends 79′, 79′ are preferably configured so thatduring use, the suction head 50 of the retrieval device 30 is angled atan angle of at least 25° relative to the central axis of the distal endportion of the ureteroscope 40. To achieve this result, the angles 70α,70α′ illustrated in FIG. 8 are preferably 120° while the angles 70β,70β′ are 30°.

Connecting the suction head to a shaft cover 70 possessing theconfiguration shown in FIG. 8 imparts the following operationalcharacteristics to the retrieving device. FIG. 10A illustrates the shaftcover 70 connected to the suction head 50, while the proximal portion 70d of the proximal section 77, the intermediate portion 70 c of theproximal section 77 and a part of the distal portion 70 b of theproximal section 77 are located in the instrument channel of theureteroscope 40. The distal section 75 of the shaft cover 70, theintermediately located bent section 79 of the shaft cover 70 and a partof the distal portion 70 b of the proximal section 77 of the shaft cover70 are positioned outside the ureteroscope 40 as shown in FIG. 10A. Inthis position, the central axis 50 a of the suction head 50 is parallelto, and offset from, the central axis 40 a of the distal end portion ofthe ureteroscope 40. The coaxial arrangement of the suction head 50relative to the ureteroscope 40 is used when advancing the retrievingdevice through the living body in regions that are not highly curved.

Starting at the position shown in FIG. 10A, axially moving (pulling) theshaft cover 70 in the proximal direction (i.e., moving the shaft cover70 in the rearward direction indicated by the rightward arrow in FIG.10A) causes the remaining part of the distal portion 70 b of theproximal section 77 of the cover shaft to enter the instrument channel42 in the ureteroscope 40, and also causes a part of the bent section 79of the shaft cover 70 to enter the instrument channel 42 in theureteroscope 40. The retrieval device 30 thus takes on the arrangementor configuration shown in FIG. 10B.

As shown in FIG. 10B, axially moving a portion of the bent section 79 ofthe shaft cover 70 into the instrument channel in the ureteroscope 40causes the suction head 50 to be angled relative to the ureteroscope 40.In particular, the central axis 50 a of the suction head 50 is orientedat an angle (i.e., an angle other than 0° and 180°) relative to thecentral axis 40 a of the distal end portion of the ureteroscope 40. Theangle between the central axis 50 a of the suction head 50 and thecentral axis 40 a of the ureteroscope 40 is preferably at least 25°,more preferably at least 30°. Angling the suction head 50 relative tothe ureteroscope 40 in this manner allows the suction head 50 to accesshighly curved regions in a living body that might otherwise be verydifficult to access with the suction head orientation shown in FIG. 10A.

As an example, reference is made to the FIG. 5 schematic illustration ofa kidney possessing a lower calix (lower renal calix) 102, a middle orintermediate calix (middle or intermediate renal calix) 104, an uppercalix (upper renal calix) 106, and a renal pelvis 101 spaced from thecalices 102, 104, 106. To reach calculus in the lower calix 102 requiresaccess by way of the ureter 108 along a path generally indicated by thedotted line FIG. 5. As can be readily appreciated, this path is highlycurved and can be difficult to navigate.

Configuring the retrieval device 30 to include the shaft cover 70illustrated in FIG. 8, it is possible to angle the suction head 50 ofthe retrieval device 30 relative to the ureteroscope 40 in the mannerillustrated in FIG. 10B by axially moving the shaft cover in therearward direction, thus making it easier to traverse or navigate thepath indicated by the dotted line in FIG. 5. It is thus possible toretrieve calculus in the lower calix 102 and move the retrievedcalculus/calculi to the middle or intermediate calix 104 or possibly theupper calix 106. Lithotripsy can then be more easily carried out withrespect to the retrieved and moved calculus.

FIG. 10C illustrates the retrieval device 30 in a position that is thesame as shown in FIG. 10B, except that the shaft cover 70 is rotated sothat the suction head 50 is angled at an orientation 180° relative tothe orientation shown in FIG. 10B. In the position shown in FIG. 10C,the suction head 50 is angled relative to the ureteroscope 40 so thatthe angle between the central axis 50 a of the suction head 50 and thecentral axis 40 a of the ureteroscope 40 is preferably at least 25°,more preferably at least 30°. There are benefits associated with beingable to rotate the shaft cover 70 and the suction head 50 from the FIG.10B position to the FIG. 10C position. An ureteroscope is typicallyequipped with the ability to deflect, but the manner of bending istypically somewhat limited. That is, the movement of the tip portion ofthe ureteroscope is limited to one plane (uniplanar movement or X-planemovement). It is thus difficult for an operator to freely control thedirection or orientation of the suction head relying only on theureteroscope deflection ability. On the other hand, when the operatorrotates the angled suction head from FIG. 10B to FIG. 10C, the differentplane of movement of the suction head (y-plane movement) is added to theplane of movement ability of the ureteroscope. Further, if the operatorpushes/pulls the shaft cover 70, a still further movement direction isadded (z-plane). That is why the operator can control the direction ofthe suction head freely by rotation (between FIG. 10B and FIG. 10C) ofthe angled-suction head. From another point of view, the installationlocation of an objective lens of the ureteroscope is off-center. So ifthe operator rotates the angled suction head from the FIG. 10B positionto the FIG. 10C position, operator can change the view of the suctionhead 50.

FIG. 10D illustrates the retrieving device in which the shaft cover 70and the suction head 50 are axially moved in the forward direction(i.e., to the right, as indicated by the arrow, in FIG. 10D). Thiscauses the suction head 50 to move axially forward, and shift to aposition in which the central axis 50 a of the suction head 50 isparallel to and offset (not coaxial) from the central axis 40 a of thedistal end portion of the ureteroscope 40. This permits a field of view100 for the operator using the optical system in the ureteroscope 40.

FIG. 10E illustrates another operational aspect of the retrieving device30. With the retrieving device 30 in the position shown in FIG. 10B (orFIG. 10C), the operator can axially pull-back the shaft cover 70 (i.e.,move the shaft cover 70, together with the suction head 50 and the shaft72) so that the shaft cover 70 is moved into the elongated body 40(ureteroscope), to straighten the bent section 79. The total length ofthe tip portion of the device (the suction head+the exposed or uncoveredportion of the shaft cover 70+the unbendable distal end portion of theureteroscope) is shorter compared to the total length of the tip portionin FIG. 10B. The operational position of the retrieving device shown inFIG. 10E is advantageous when moving or maneuvering the retrievingdevice into a narrow lumen (e.g., an ureter and an ureteral accesssheath).

FIGS. 11A-11C illustrates an embodiment representing another example ofthe inventive retrieving device disclosed here. The embodiment shown inFIGS. 11A-11C represents an alternative way of angling the suction headrelative to the distal end portion of the ureteroscope. This embodimentof the retrieving device depicted in FIGS. 11A-11C is similar to theembodiment described above and illustrated in FIGS. 10A-10D, except thatthe angling of the suction head is facilitated by a shaped contact partrather than a shaped tube.

Referring to FIG. 11A, a contact part 180 is provided between thesuction head 150 and the ureteroscope 40. In this embodiment, thecontact part 180 is integrally formed in one piece at the same time withthe suction head 150. The contact part 180 projects rearwardly (in theproximal direction) away from the suction head 150 as illustrated inFIG. 11A. The contact part 180 in this embodiment is a curved projectingportion. The contact part 180 includes a curved surface 181, namely aconvex surface. The retrieval device 130 further includes a shaft cover70′ is a linearly extending (straight) shaft cover 70′. FIG. 11A showsthat the shaft cover 70′passes through a hole in the contact part 180 sothat the contact part 180 at least partially surrounds the shaft cover70′.

The shaft cover 70′ passes through a hole in the contact part 180 at anangle in FIG. 11A so that the central axis of the suction head 150 andthe central axis of the distal end portion of the shaft cover 70′ areparallel to one another, but offset from one another so that the suctionhead 150 and the distal end portion of the shaft cover 70′ are notcoaxial with one another. This offset contributes to angling the suctionhead by the shaped contact part in FIGS. 11-16. The suction head 150 andthe distal end portion of the ureteroscope 40 shown in FIG. 11A areoriented in the manner shown in FIG. 11A while advancing the retrievaldevice 130 within the narrow lumen (e.g., an ureter or an ureteralaccess sheath). To manipulate or move the retrieval device through arelatively narrow lumen or to retrieve calculus in a narrow lumen, theoperator tends to choose or may prefer the device being in the stateshown in FIG. 11A. To manipulate or move the retrieval device through acurved area (e.g., to reach a lower calix (lower renal calix)), theoperator tends to choose or may prefer the device being in the statedepicted in FIG. 11B. To retrieve calculus in a large area (e.g., anopen space in kidney), the operator can use the device positioned ineither the state shown in FIG. 11A or the state shown in FIG. 11B.

To angle the suction head 150 relative to the distal end portion of theureteroscope 140, at first the shaft cover 70′ is axially moved orpulled rearwardly (i.e., to the right, in the direction of the arrow, inFIG. 11A) until the contact part 180 comes into direct contact with thecurved (concave) distal end surface 41 of the ureteroscope 40. In thisstate (the curved surface of the contact part 180 just contacts thedistal end surface 41 of the ureteroscope 40), the suction head 150 isnot angled. As the shaft cover 70′ continues to be axially moved in therearward direction, this contact between the two curved surfaces 181, 41helps cause the suction head 150 to become angled relative to the distalend portion of the ureteroscope 40 as illustrated in FIG. 11B. It isthus possible to angle the suction head 50 relative to the ureteroscope40 by axially moving the shaft cover (and the suction head 50).

From the position illustrated in FIG. 11A, it is possible to rotate thesuction head 150 by rotating the shaft cover 70′. The suction head 150is moved to the position shown in FIG. 11C which is displaced 180° fromthe position shown in FIG. 11A. In the position of the suction head 150shown in FIG. 11A, the suction head 150 and the distal end portion ofthe ureteroscope 40 are parallel and coaxial with one another. Byrotating the suction head 150 to the FIG. 11C 11A position, the operatorcan pass the retrieval device 130 into a relatively narrow lumen (e.g. aureter and a ureteral access sheath). In the position of the suctionhead 150 shown in FIG. 11C, the suction head 150 does not obstruct thefield of view 110 seen through the objective lens of the ureteroscope40. By rotating the suction head 150 in this way, the medicalprofessional can observe in front of the retrieval device 130 to helpfacilitate the procedure.

FIGS. 12A and 12B illustrate another embodiment. This embodiment of theretrieval device 230 is similar to the embodiment illustrated in FIGS.11A-11C, except that the configuration of the contact part is different.The embodiment of the retrieval device 230 shown in FIGS. 12A-12Bincludes a contact part 280 that includes two sections 282, 284connected to one another by a hinge 283. The two sections 282, 284 canbe plate-shaped elements. One of the sections 282 is fixed to orintegral with the suction head 250, and the other section 284 possessesa through hole through which the shaft cover 70′ passes. The section 284thus partially surrounds the shaft cover 70′. The shaft cover 70′ is alinearly extending (straight) shaft cover 70′

In operation, the shaft cover 70′ is moved axially in the rearwarddirection (i.e., to the right, in the direction of the arrow, in FIG.12A) and the contact part 280 approaches the curved (concavely curved)distal end surface 41 of the ureteroscope 40 and ultimately contacts theconcavely curved distal end surface 41 of the ureteroscope 40. After thesection 282 of the contact part contacts the concavely shaped distal endsurface of the ureteroscope 40, continued axial movement of the shaftcover 70′ in the proximal or rearward direction causes the suction head250 to become angled relative to the distal end portion of theureteroscope as shown in FIG. 12B. In this way, the central axis of thesuction head 250 forms an angle (i.e., an angle other than 0° and 180°)relative to the central axis of the distal end portion of theureteroscope 40. The suction head 250 is preferably angled at an angleof at least 25° relative to the central axis of the distal end portionof the ureteroscope 40, more preferably at least 30°. The section 284can help stabilize the contact between the section 282 and the distalend surface of the ureteroscope 40.

FIGS. 13A and 13B illustrate an embodiment representing another exampleof the retrieving device disclosed here in which the retrieving deviceis configured to angle the suction head relative to the ureteroscope.This embodiment of the retrieving device differs from the version shownin FIGS. 12A and 12B in that the contact part 380 is a rigid one-piecemember. The contact part 380 is integrally formed in one piece with thesuction head 350, but can also be separate from the suction head 350 andfixed in place to the suction head 350. The contact part 380 includes anarm 386 projecting away from the suction head 350, and a hemisphericalportion 388 configured to contact the concave curved distal end surface41 of the ureteroscope 40. The hemispherical shaped portion 388 presentsa convex surface that directly contacts the concave curved distal endsurface 14 of the ureteroscope 40. The hemispherical shaped portion 388of the contact part 380 includes a through hole or opening through whichpasses the shaft cover 70′ so that a portion of the contact part 380encircles or surrounds the shaft cover 70′. The shaft cover 70′ is alinearly extending (straight) shaft cover 70′

In use, the shaft cover 70′ is axially moved in the rearward direction(i.e., to the right, in the direction of the arrow, in FIG. 13A). Thiscauses the suction head 350 and the contact portion 380 to also move inthe rearward direction until the hemispherical shaped portion 388directly contacts the distal end surface of the ureteroscope 40.Continued rearward axial movement of the shaft cover 70′ causes thesuction head 350 to pivot in the manner indicated by the arrow in FIG.13B so that the suction head 350 is angled relative to the ureteroscope40. That is, the central axis of the suction head 350 is angled at anangle of at least 25°, preferably at least 30°, relative to the centralaxis of the distal end portion of the ureteroscope 40.

FIGS. 14A and 14B illustrate an embodiment representing a furtherexample of the retrieving device disclosed here in which the retrievingdevice is configured to angle the suction head relative to theureteroscope. This embodiment of the retrieving device 430 utilizes acontact part 480 that is separate from both the suction head 450 and theureteroscope 40, but is subsequently mounted on or connected to thedistal end portion of the ureteroscope 40. The contact part 480 is agenerally U-shaped member defined by two spaced-apart legs 492, 494connected by an intermediately located base 496. The leg 492 closest tothe suction head includes a curved surface 497 facing towards thesuction head. A hollow cylindrical element 498 is integrally formed withone of the legs 494 and projects away from the leg 494. The cylindricalelement 498 is positioned in the instrument channel 42 at the distal endportion of the ureteroscope 40 so that the contact part 480 isintegrated with and held in the ureteroscope 40.

Each of the legs 492, 494 of the contact part 480 is provided with athrough hole 493, 495 through which passes the shaft cover 70′. Theshaft cover 70′ is a linearly extending (straight) shaft cover 70′. Byvirtue of the through holes 493, 495 in the legs 492, 494 of the contactpart 480, a portion of the contact part 480 surrounds the shaft cover 70at two spaced apart locations. The shaft cover 70′ forming a part of theretrieval device 430 shown in FIGS. 14A and 14B is a linearly extending(straight) tube. The shaft cover 70′ passes through holes 493 and/or 495in the contact part 180 at an angle as shown in FIG. 14A so that thecentral axis of the suction head 450 and the central axis of the distalend portion of the shaft cover 70′ are parallel to one another, butoffset from one another so that the suction head 450 and the distal endportion of the shaft cover 70′ are not coaxial.

In use, the contact part 480 is fitted to the ureteroscope 40 bypositioning the cylindrical element 498 in the instrument channel 42 atthe distal end portion of the ureteroscope 40. The shaft cover 70′ isthen axially moved in the proximal direction (i.e., to the right, in thedirection of the arrow, in FIG. 14A). This causes the suction head 450to approach the ureteroscope 40 and eventually move into direct contactwith the curved surface 497 on the leg 492 of the contact part 480. Asthe shaft cover 70′ continues to be axially moved (pulled) in theproximal direction, the suction head 450 becomes angled by virtue of thecurved surface 497 of the leg 492 of the contact part 480 contacting thesuction head 450 so that the suction head 450 becomes angled withrespect to the ureteroscope.

FIGS. 15A and 15B illustrate an embodiment of the retrieving devicerepresenting another example of the inventive retrieving devicedisclosed here. This embodiment of the retrieving device 530 includes acontact part 580 that is separate from both the suction head 550 and theureteroscope 40. The contact part 580 is a generally V-shaped one-piececontact part that includes two legs 582, 584 connected to one another ata vertex. The two legs 582, 584 diverge away from one another in adirection away from the vertex. Each of the legs 582, 584 includes arespective through hole 593, 595 through which extends the shaft cover70′. A portion of the contact part 580 thus encircles or surrounds theshaft cover 70′ at two spaced apart locations. The shaft cover 70′ is alinearly extending (straight) shaft cover 70′.

In use, the shaft cover 70′ is axially moved in the proximal direction(i.e., to the right, in the direction of the arrow, in FIG. 15A). Thiscauses the suction head 550 to also move in the proximal direction.Eventually, the suction head 550 contacts the leg 582 of the contactpart 580, and the leg 584 of the contact part 580 contacts the distalend of the ureteroscope 40. As the shaft cover 70′ continues to beaxially moved (pulled) in the proximal direction, the suction head 550becomes angled by V-shaped contact part 580 contacting both the suctionhead 550 and the distal end of the ureteroscope 40 so that the suctionhead 550 becomes angled with respect to the ureteroscope 40 in themanner illustrated in FIG. 15B. That is, the suction head 550 moves inthe direction of the arrow in FIG. 15B so that the central axis of thesuction head 550 is disposed at an angle (other than 0° and 180°)relative to the central axis of the distal end portion of theureteroscope 40. That is, the central axis of the suction head 550 isangled at an angle of at least 25°, preferably at least 30°, relative tothe central axis of the distal end portion of the ureteroscope 40.

It is possible to control the angle of inclination of the suction head550 relative to the ureteroscope 40 in the embodiment shown in FIGS. 15Aand 15B by appropriately selecting the material forming the contact part580. For example, the contact part 580 can be made of a relatively rigidmaterial, like metal, so that the two legs 582, 584 are relatively stiffand maintain the relative position/orientation when the leg 582 iscontacted by the suction head 550 and the leg 584 contacts the distalend of the ureteroscope 40. On the other hand, the contact part 580 canbe made of a more flexible material such that in the arrangement shownin FIG. 15B, continued axial movement of the shaft cover 70′ in theproximal or rearward direction varies the angle between the suction head550 and the ureteroscope 40.

FIGS. 16A-16C illustrate an embodiment representing another example ofthe retrieving device disclosed here. This embodiment of the retrievingdevice 630 provides another mechanism for angling the suction head 650relative to the ureteroscope 40. This embodiment incudes a contact partcomprised of two separate contact sections 681, 683. The first contactsection 681 is connected to or fixed to the suction head 650 so that thefirst contact section 681 and the suction head 650 move together as aunit, while the second contact section 683 includes a cylindrical-shapedprojection 683′ that fits into the instrument channel at the distal endportion of the ureteroscope 40 so that the second contact section 683and the suction head 650 move together as a unit. The second contactsection 683 is thus integrated with or connected to the ureteroscope 40.The first and second contact sections 681, 683 each include a respectiveinclined face or surface 681″, 683″. Each of these first and secondcontact sections 681, 683 also includes a through hole or openingthrough which extends the shaft cover 70′. In this embodiment, the shaftcover 70′ is a linearly extending (straight) shaft cover 70′. Each ofthe contact sections 681, 683 thus encircles a portion of the shaftcover 70′.

Two projections 681 a, 681 a project from the inclined surface 681″ ofthe first contact section 681 toward the second contact section 683. Tworecesses 683 a, 683 a are provided in the inclined surface 683″ of thesecond contact section 683. Each of the recesses 683 a, 683 a isconfigured to receive one of the projections 681 a, 681 a projectingfrom the first contact part 681.

In use, the shaft cover 70′ is axially moved in the proximal direction(i.e., in the rearward direction, indicated by the arrow, in FIG. 16B)so that the suction head 650 approaches the ureteroscope 40. Eventually,each of the projections 681 a, 681 a projecting from the first contactsection 681 enters the respective recess 683 a, 683 a in the secondcontact section 683 as shown in FIG. 16B. The suction head 650 and theureteroscope 40 are thus locked together (rotationally locked together).In the arrangement shown in FIG. 16B, the retrieval device 630 is movedthrough the relatively narrow lumen of the living body toward thedesired location.

To angle the suction head 650 relative to the distal end portion of theureteroscope 40, the first and second contact sections 681, 683 areseparated from one another so that the projections 681 a, 681 a areseparated (spaced) from the respective recess 683 a. The first contactsection 681 is rotated 180° relative to the second contact section 683as illustrated by the arrow in FIG. 16C. This can be accomplished byrotating the shaft cover 70′ and the suction head 650 relative to theureteroscope 40. After rotating the first contact section 681, theprojections 681 a, 681 a projecting from the first contact section 681are fitted into respective recesses in the second contact section 683 asillustrated in FIG. 16C. In the angled orientation shown in FIG. 16C,the recesses in the second contact part 683 that receive the projections681 a, 681 a differ from (i.e., are angled differently than) therecesses 683 a, 683 a shown in FIG. 16A.

This embodiment of the retrieving device 630 provides a fixed angularorientation between the central axis of the suction head 650 and thecentral axis of the distal end portion of the ureteroscope 40. Thisangular orientation is defined by the angle of the inclined faces 681″,683″ of the first and second contact sections 681, 683. It is possibleto adjust the angular orientation by changing the angle of inclinationof the inclined surfaces 681″, 683″.

Each of the embodiments of the retrieving device disclosed above forangularly orientating the suction head relative to the distal endportion of the ureteroscope 40 makes it possible to angularly positionthe suction head by axially moving the shaft cover and the suction headrelative to the ureteroscope. It is thus possible to achieve a desiredangular orientation of the suction head without excessive effort andwithout a complicated construction.

The detailed description above describes a device and method forretrieving/removing calculus from parts of a living body such as theureter and the renal pelvis. The invention is not limited, however, tothe precise embodiments and variations described. Various changes,modifications and equivalents can effected by one skilled in the artwithout departing from the spirit and scope of the invention as definedin the accompanying claims. It is expressly intended that all suchchanges, modifications and equivalents which fall within the scope ofthe claims are embraced by the claims.

What is claimed is:
 1. A device for retrieving calculus in a lumen of a living body comprising: a shaft; an elongated member sized to be positioned in the lumen of the living body, the elongated member including a suction head housing possessing a distal end, a proximal end and an interior, the distal end of the suction head housing being open to permit entry of calculus and the proximal end of the suction head housing being closed by a wall through which passes the shaft; a rotatable impeller positioned inside the elongated member; the shaft being connected to the rotatable impeller so that the shaft and the rotatable impeller rotate together as a unit, the shaft being connectable to a drive source that is operable to rotate the shaft and the rotatable impeller, with rotation of the rotatable impeller creating suction that draws calculus through the open distal end of the suction head housing and into the interior of the suction head housing; a shaft cover possessing a distal end portion that terminates in a distal end connected to the proximal end of the suction head housing so that the elongated member and the shaft cover axially move and rotate together, the distal end portion of the shaft cover possessing a central axis, the shaft cover also possessing a proximal end portion that possesses a central axis, the shaft cover covering the shaft; and the central axis of the distal end portion of the shaft cover and the central axis of the proximal end portion of the shaft cover being non-coaxial.
 2. The device according to claim 1, wherein the shaft cover includes an intermediate portion between the distal end portion of the shaft cover and the proximal end portion of the shaft cover, the intermediate portion being a bent portion that is bent when no force is applied to the bent portion, the shaft cover being movably positionable in a lumen of an elongated body to move between: i) one position in which the distal end portion of the shaft cover is positioned at an inlet to the lumen and the bent portion is located in the lumen so that an angle is formed between the central axis of the elongated member and a central axis of a distal section of the elongated body; and ii) an other position in which the bent portion is positioned at the inlet to the lumen while the distal end portion is positioned outside the elongated body so that the angle between the central axis of the elongated member and the central axis of the distal section of the elongated body in the second position is less than the angle between the central axis of the elongated member and the central axis of the distal section of the elongated body in the first position of the shaft cover.
 3. The device according to claim 2, wherein the elongated body is an ureteroscope.
 4. The device according to claim 1, wherein the proximal end portion of the shaft cover is a linearly extending proximal end portion and the distal end portion of the shaft cover is a linearly extending distal end portion.
 5. The device according to claim 4, wherein the linearly extending proximal end portion and the linearly extending distal end portion each possess an axial extent, the axial extent of the linearly extending proximal end portion being greater than the axial extent of the linearly extending distal end portion.
 6. The device according to claim 1, wherein a proximal end portion of the suction head housing is a contact part configured to cause the suction head housing to angularly move relative to the distal end portion of the elongated body when the shaft cover together with the suction head housing is axially moved in a proximal direction relative to an elongated body so that the central axis of the suction head housing is angled relative to the central axis of the distal end portion of the elongated body at an angle other than 0° and 180°.
 7. The device according to claim 1, wherein the proximal end portion of the shaft cover is a linearly extending proximal end portion and the distal end portion of the shaft cover is a linearly extending distal end portion, the linearly extending proximal end portion and the linearly extending distal end portion being parallel to one another.
 8. A device for retrieving calculus in a lumen of a living body comprising: an elongated member sized to be positioned in the lumen of the living body, the elongated member including a suction head housing disposed on a distal side of the elongated member; a rotatable member positioned inside the elongated member; a shaft connected to the rotatable member so that the shaft and the rotatable member move together as a unit, the shaft being connectable to a drive source to rotate the shaft and the rotatable member, with rotation of the rotatable member creating suction that draws calculus toward the elongated member; a shaft cover possessing a distal end portion having a central axis and a proximal end portion having a central axis, the shaft cover covering the shaft and being connected to the elongated member so that the elongated member and the shaft cover axially move and rotate together; and the central axis of the distal end portion of the shaft cover is offset from the central axis of the proximal end portion of the shaft cover.
 9. The device according to claim 8, wherein the shaft cover includes a bent section that is bent when no force is applied to the bent section, the bent section being positioned proximally of a distal section of the shaft cover, and the shaft cover being movably positionable in a lumen of an elongated body to move between: i) one position in which the distal section of the shaft cover is positioned at an inlet to the lumen and the bent section is located in the lumen so that an angle is formed between the central axis of the elongated member and a central axis of a distal section of the elongated body; and ii) an other position in which the bent section is positioned at the inlet to the lumen while the distal section is positioned outside the elongated body so that the angle between the central axis of the elongated member and the central axis of the distal section of the elongated body in the second position is less than the angle between the central axis of the elongated member and the central axis of the distal section of the elongated body in the first position of the shaft cover
 10. The device according to claim 9, wherein the shaft cover includes a linearly extending proximal section positioned proximal of the bent section, the distal section being a linearly extending distal section, the proximal section possessing a central axis and the distal section possessing a central axis, the central axis of the distal section and the central axis of the proximal section being non-coaxially arranged.
 11. The device according to claim 9, wherein the shaft cover includes a linearly extending proximal section positioned proximal of the bent section, the distal section being a linearly extending distal section, the linearly extending proximal section and the linearly extending distal sections each possessing an axial extent, the axial extent of the linearly extending proximal section being greater than the axial extent of the linearly extending distal section.
 12. The device according to claim 9, wherein the elongated body is an ureteroscope.
 13. The device according to claim 9, wherein a contact part is disposed on a proximal side of the suction head housing, the contact part being configured to cause the suction head housing to angularly move relative to the distal end portion of the elongated body when the shaft cover together with the suction head housing is axially moved in a proximal direction relative to an elongated body so that the central axis of the suction head housing is angled relative to the central axis of the distal end portion of the elongated body at an angle other than 0° and 180°.
 14. The device according to claim 13, wherein the contact part is integrally formed in one piece at the same time with the suction head housing.
 15. The device according to claim 13, wherein the contact part possesses a curved portion that contacts the distal end of the elongated body when the shaft cover together with the suction head is axially moved in the proximal direction relative to the elongated body to cause the suction head housing to be angled relative to the distal end portion of the elongated body.
 16. The device according to claim 13, wherein the contact part surrounds at least a part of the shaft cover.
 17. The device according to claim 13, wherein the contact part is separate from the suction head housing and is separate from the elongated body, the contact part including a projection fitted into the lumen in the elongated body.
 18. The device according to claim 13, wherein suction head housing possesses a proximal end facing towards the elongated body, wherein the contact part is separate from the suction head housing and is separate from the elongated body, the contact part possessing a curved end portion that contacts the proximal end of the suction head housing when the shaft cover is moved proximally relative to the elongated body.
 19. The device according to claim 13, wherein the elongated body is a ureteroscope. 